Lubricating oil and process of producing the same



Patented July 19, 1932 UNITED STATES PATENT OFFICE THEODORE W. DOELL, 0F BERKELEY, CALIFORNIA, ASSIGNOR TO STANDARD OIL COM- PANY OF CALIFORNIA, OF. SAN FRANCISCO, CALIFORNIA, A CORPORATION OF DELA- WARE LUBRICATING- OIL AND PROCESS OF PRODUCING THE SAME No Drawing.

This invention relates to an oil for use in internal combustion engines and, although it can be used with any type of internal combustion engine, it is particularly adapted to use with certain well known automobiles having a planetary transmission Controlled by metallic bands having fabric linings.

In automobiles of this type the crank case is ordinarily in open communication with the transmission case thus permitting the oil in the crank case to enter the transmission case. A single type of lubricant is used for lubricating both the engine and the transmission, although the lubrication requirements for these two parts of the automobile are quite different. An ordinary oil suitable for engine lubrication will often cause the linings of the transmission bands to become brittle and acquire a hard, glazed'surface which causes the bands alternately to seize and slip thus causing a vibration of the entire car, commonly known as-chattering. Chattering is encountered mainly when operating the foot brake, and to a lesser extent by seizure of the reverse and low speed bands.

The object of the present invention is to provide a lubricating oil which will substantially eliminate chattering Another object is to provide an oil which is stable in service and storage, particularly in the presence of moisture.

Another object is to provide an oil which will not cause sticking or gumming of the piston rings or valve stems.

Another object is to produce an oil which will not give excessive carbon formation which leads to cylinder wear.

Various lubricating oils have been made heretofore for the purpose of preventing the chattering of planetary transmission bands but the desired result has usually been obtained at the expense of Other desirable qual' ities of the oil. Some non-chattering oils decompose upon standing in storage. Others deposit an excessive amount of carbon on the pistons and cylinder head, cause gummingof the piston rings, increase the oil consumption and reduce the available horsepower of the motor. Other non-chattering oils have unsatisfactory viscosity curves, being too viscous Application filed August 24,1927. Serial No. 215,260.

at low temperatures. Some such oils have a tendency to foam while others lose a part of their oily quality.

A common method of preparing non-chattering oils is to mix a small quantity of animal or vegetable oil with a larger quantity of suitable mineral lubricating oil. Another method is to mix with the mineral oil various amounts of certain soaps such as aluminum or sodium soaps. Another method is to mix a small amount of mineral castor oil with a larger amount of mineral oil. All of these methods are unsatisfactory largely for one or another of the reasons hereinbefore enumerated.

The present invention comprises a lubricating oil in which the foregoing disadvantages, are overcome. This lubricant is made by adding to a lubricating oil a small amount of a lead soap, preferably a lead soup of the higher, unsaturated fatty acids, together with salts of sulfonates, such as those derived from the treatment of petroleum oils with sulfuric acid. The lead salts of the saturated fatty acids are nearly insoluble in oil, whereas lead oleate, linoleate, ricinoleate or, in short, the lead salts of the most frequently occurring unsaturated acids are soluble in oil and adaptable to the produc tion of chatter-preventing oils. lVhile it is most convenient and economical to make use of oleic acid in the preparation of the lead soap base it is possible that triglycerides (Whole fats or fatty oils) such as triolein, linseed oil, castor oil, etc. could be used.

While the use of lead soaps, particularly lead oleate, in lubricatin oils has been disclosed, such use has not een successful, as the oils thus compounded are not always stable, and when subjected to the presence of moisture, either during use in equipment or by exposure to moist atmosphere during long periods of storage, there is a tendency for the soap base to separate and settle to the bottom of the mixture. Y

I have found that the stability of a compounded lubricating oil may be greatly increased-by the addition of a small amount of a salt of a sulfonate or sulfonates or sulfonic acids. These sulfonates or sulfonic acids, preferably oil soluble, may be obtained in any suitable manner from acid treated petroleum oils. Although their structure is complex and not completely known, the terms sulfonates or sulfonic acids refers to a definite series or group of compounds so known in the art.

Of the various metallic salts of sulfonic acids such as sodium, aluminum, copper or calcium, I prefer to use the lead salt. Furthermore, I have found that although good results are obtained by mixing the lead soap of an unsaturated fatty acid with a metallic salt of a sulfonate, improved results are obtained by forming the lead soap and metallic sulfonate simultaneously from a solution or suspension containin the sulfonate and the desired soap. This 0 j ect can be obtained by forming a mixture of the sulfonic and oleic acids, for example, simultaneously saponifying with alkali, and then simultaneously pre-.

cipitating with a lead salt (preferably water soluble) so as to produce a lead oleate-sulfonate. When thus prepared, a complex or double compound is probably formed (although such is not positively known to be true) which I term a metallic oleate sulfonate. A small amount of this product is then added to a suitable mineral lubricating oil and a superior, stable, chatterless oil produced. The term metallic-oleate-sulfonate as used herein illustrates and embraces mixtures or compounds of metallic soaps of higher unsaturated fatty acids and of sulfonic acids, such as sodium, aluminum, copper or calcium, but preferably lead soaps.

In order to enable others skilled in the art to practice my invention I will now describe in more detail a preferred method. In order to obtain the sulfonic acids, I take acid treated oil, for example, oil treated with strong sulfuric acid, and neutralize with an alkali such as caustic soda. About 30% by volume of alcohol or other solvent is then added, the mixture gently agitated, heated to about 160 F. (when alcohol is used) and allowed to settle. The alcohol serves to extract the oil soluble sulfonate. The alcohol solution of sulfonates settles to the bottom of the mixture and is drawn off. The alcohol is removed b distillation, the sulfonates strongly acidi ed with hydrochloric or other acid, agitated and the acid layer removed.

' The oily layer, consisting of sulfonic acids, is

taken up with naphtha or other petroleum fraction, (a distillate of 250 F. to 350 F. boiling range has been successfully used), washed until free of mineral acid and the naphtha distilled off. The resulting sulfonic acids are then ready for further treatment.

Sulfonic acids are then mixed with an unsaturated fatty acid such as oleic (approximately equal amounts by weight produce good I results) and the mixture heated to about 125 F.180 F. The acids are then neutralized with caustic soda, care being taken not to overreach the point of neutrality appreciably and diluted with water. An aqueous solution of a lead salt such as lead acetate is then added, the solution becoming cloudy as the lead salts of oleic and sulfonic acids are formed. Suflicient lead acetate is added to precipitate all acids. The temperature of the batch during this period is preferably about 180 F. termed by me lead-oleate-sulfonate. This .productmay then be washed with water and quickly dried at a temperature of about 250- 325 F.

The prepared lead-oleate-sulfonate may be added directly to the lubricating oil in amounts of 0.1 to 3% by Weight, or it may be first dissolved in two or three times its weight of lubricating oil, thereby forming a concentrated soap base which may then be added to suitable lubricating oils to render them stable, chatterless and of generally improved quality.

Instead of sulfonates derived from pctroleum oils I may use Turkey-red oil or ricinol-sulfonates. Turkey red oils are commercial products obtained by treating Castor oil with concentrated sulfuric acid and then Washing with sodium sulfate followed by partial neutralization with an alkali. These ricinol-sulfonates may be treated in the same manner as the oil soluble sulfonates from petroleum, that is, acidified, taken up with naphtha, Washed, and naphtha distilled off. The sulfo-ricinoleic acid thus produced is used in the same manner as sulfonic acid except that the final product may be termed lead oleate-sulfo-ricinate.

It is pointed out that the final product is a lubricating oil containing a small percentage of lead-oleate sulfonate or lead-oleate sulfo-ricinate (or any other unsaturated fatty acid instead of oleic) and should not be confused with lubricating oils or greases containing larger amounts of soaps without the stabilizing sulfonates. The product of the present invention contains an insufficient amount of the soap base' to form a semi-solid as grease. In fact the preferred amount of soap base added is sufliciently low to have substantially no effect upon the viscosity of the lubricating oil.

Obviously the proportions and methods described in the foregoing preferred embodiment of the invention may be varied considerably, and my invention is not to be considered as limited to the exact figures set forth herein but is of the scope of the following claims.

I claim: 1. A fluid lubricating oil containing a mineral lubricating oil, and lead salts of unsaturated fatty acid and of sulfonic acid.

The precipitated soaps are 2. A fluid lubricating oil containing a mineral lubricating oil, and lead salts of oleic acid and of sulfonic acid.

3. A fluid lubricating oil containing a mineral lubricating oil and lead-oleate-sulfonate.

4. A fluid lubricating oil containing amineral lubricating oil and a complex lead salt of oleic and sulfonic acids in solution.

5. A fluid lubricating oil containing a mineral lubricating oil, a complex lead salt of nsaturated fatty acid and sulfo-ricinoleic aci 6. A lubricating oil containing a mineral lubricating oil, lead soap of unsaturated fatty acid and lead salts of sulfonic acids, said lead compounds being present in amounts insufficlient to effect the viscosity of the lubricating o1 7. A process of making fluid lubricating oils comprising adding lead salts of oleic acid and of a sulfonic acid to a mineral lubricating oil.

8. A process of making lubricating oils comprising dissolving a lead-oleate-sulfonate in a mineral lubricating oil.

9. A process of making lubricating oils comprising dissolving a lead-oleate-sulforicinate in a mineral lubricating oil.

10. A process of makin lubricating oils comprising adding a lea salt of an unsaturated fatty acid and a lead salt of a sulfonic acid to mineral lubricating oil, said salts being added in quantity insufiicient to materially aflect the viscosity of the lubricating oil.

11. A process of making fluid lubricating oils comprising mixing unsaturated fatty acids with sulfonic acids, simultaneously producinglead salts of said acids, washing and drying such lead salts and then dissolving such salts in a mineral lubricating oil.

12. A process of making fluid lubricating oils comprising mixing oleic acid with sulfonic acids, simultaneously producing lead salts of said acids, and then dissolving such salts in a mineral lubricatin oil.

13. A process of making uid lubricating oils comprising mixing oleic acid with sul- \LEOIIIC acids, neutralizing said acids, simultaneously producing lead salts of said acids by means of an aqueous lead salt solution, and then dissolving such salts in a mineral lubricating oil.

14. A process of making fluid lubricating oils comprising adding lead salts of an unsaturated fatty acid and of a sulfonic acid to a mineral lubricatin oil.

15. In a process of ma ing fluid lubricating oils the. steps of mixing unsaturated fatty acids with sulfo-ricinoleic acids, simultane ously producing lead salts of said acids, and then dissolving such salts in a fluid mineral lubricating oil.

16. A process of making fluid lubricating oils comprisin mixing oleic acid with sulfor icinolelc aci s, simultaneously producing lead salts of said acids, and then dissolving such salts in a fluid mineral lubricating oil.

17. A fluid lubricating 'oil containing a mineral lubricating oil, a metallic salt of a sulfonic acid, and a lead salt of an unsaturated fatty acid. A

18. A fluid lubricating oil containing a mineral lubricating oil, a metallic salt of a sulfonic acid, and a lead salt of oleic acid.

19. A fluid lubricating oil containing a mineral lubricating oil, a metallic salt of a sulfo-ricinoleic acid, and a lead salt of an unsaturated fatty acid.

20. A lubricating oil containing a mineral lubricating oil, a metallic salt of a sulfo-- ricinoleic acid, and a lead salt of oleic acid.

21. A lubricating oil containing a mineral lubricating oil, an oil soluble metallic salt of a sulfonic acid, a lead oleate, the metallic and lead salts being present in quantity insuflicient to materially affect the viscosity of the lubricatin oil.

22. In a method of making lubricating oils, the step of adding a metallic salt of a sulfonic acid and a lead salt of anunsaturated fatty acid to a mineral lubricating oil.

23. In a method of making lubricating oils, the step of adding a metallic salt of a sulfonic acid and a lead salt of oleic acid to a mineral lubricating oil.

24. In a method of making lubricating oils, the step of adding a metallic salt of a sulforicinoleic acid and a lead salt of an unsaturlated fatty acid to a mineral lubricating o1 25. In a method of making lubricating oils, the step of adding a metallic salt of a sulforicinoleic acid and a lead salt of oleic acid to a mineral lubricating oil.

26. A method of making lubricating oils comprising forming a mixture of a metallic salt of a sulfonic acid and a lead salt of an unsaturated fatty acid, and dissolving said mixture in a fluid mineral lubricating oil, said salts being dissolved in quantity insufficient' to materially aflect the viscosity of the lubricatin oil.

Signed at of August, 1927.

THEODORE W. DOELL.

ichmond, Cal. this 9th day 

